Lighting accounts for a large percentage of the world's total energy usage. Currently, the trend is to move towards lighting that employs light emitting diodes (LEDs) as they are more efficient, last longer and are more shock and vibration resistant. However, like other light sources LEDs create a significant amount of heat that must be dissipated since LEDs cannot operate at very high temperatures like traditional light sources.
Current LED lighting designs generally approach the thermal problem by adding heatsink fins on and around the housing. Some previous designs simply attach multiple light fixtures together to achieve high light output. However, this ex post facto design leads to large and bulky light fixtures that are very heavy because the heat is dissipated primarily by air flow through convection around the outside of the light fixture where the fins are located.
In addition, the heat sink fins are typically extended out further radially for light fixtures that produce more light output and, therefore, dissipate more power and heat generated by the LEDs. However, extending the heat sink fins out further radially moves the heat dissipating surface area further away from the LEDs. The additional distance away from the LED heat source results in a higher thermal resistance between the LEDs and the outside air and, therefore, less effective use of the heat sink fins and ultimately higher LED junction temperatures.